Bill Maher has history with the n-word, but doesn't understand the history behind the word ... according to Anne-Marie Johnson.
The actress tells us she wasn't surprised when Maher got blasted for saying the n-word on 'Real Time' ... because she was front and center when he did the same thing 16 years ago.
Johnson says the problem is Maher's not getting the message from black people that the word causes pain ... and she doesn't think he ever will. The difference this time is he got called out for it.
It's interesting -- Anne-Marie doesn't think Bill's racist ... just stubborn. And she doesn't seem too hopeful he'll change.
Maher's said he regretted using the word last week, but back in 2001 he got into a heated exchange with Anne-Marie on "Politically Incorrect" -- and it included multiple n-bombs.